Various kinds of electronic equipment are carried on a motor vehicle. Therefore, a wiring harness is arranged on the motor vehicle so that electric power from a power source and control signals from a computer can be supplied to the electronic equipment. The wiring harness has electric wires, terminal fittings attached to the electric wires, and other parts such as connector housings, tubes, protectors, tapes, grommets and the like.
The electric wire has a conductive core wire and an insulative covering portion covering the core wire. The electric wire is the so-called covered wire. The connector housing is made of insulative synthetic resin in a box-shape. The connector housing accommodates the terminal fittings. The terminal fittings and the connector housing constitute the connector. The tube is made of insulative and elastic synthetic resin in a cylindrical shape or a bellows-shape. The tube protects the electric wire inside thereof.
The protector is made of insulative synthetic resin, having a gutter-like cross-section. The protector accommodates the electric wire, and the tape is wound around the protector. The tape is made of flexible synthetic resin. An adhesive face is formed on one surface of the tape. The tape is wound around the electric wires or the above protector. The grommet is made of insulative and elastic synthetic resin in a cylindrical shape or a bellows-shape. The grommet lets the electric wire pass therethrough and engages a hole of a panel forming a vehicle body, while exhibiting waterproofing and sound insulation property.
With regard to the electric wire of the wiring harness, the thickness of the core wire, material (for example, from viewpoint of heat-resistance) of the covering portion, and service conditions should be distinguished. Here, the service conditions mean systems such as an air-bag system, an antilock brake system, and a power transmission system in which the electric wires are used.
The electric wires of the wiring harness are variously colored in order to distinguish the above service conditions (i.e. systems). In manufacturing the prior art electric wire, the electric wire is colored by mixing a colorant with specified color into the insulative synthetic resin when the core wire is covered with the insulative synthetic resin.
Further, the above parts are colored in various colors in order to distinguish attaching positions thereof. In manufacturing the prior art parts, a colorant with a specified color is mixed into the synthetic resin when the parts are injection-molded in a specified shape.
When the wiring harness is assembled, the electric wire and the parts are to be stocked at Step S101 of FIG. 16. Next, at Step S102, the electric wire is cut into pieces with specified lengthes, the electric wires are connected if necessary, and Step S103 is reached. At Step S103, the electric wires, the terminal fittings, and the above parts such as the connector housing and the grommet are prepared, and Step S104 is reached.
At Step S104, the parts are attached to the electric wire so as to assemble a sub-harness, and Step S105 is reached. That is, the sub-harness consists of the electric wires, the terminal fittings attached to the electric wires, and the above parts. At Step S105, the wiring harness is assembled by using the sub-harnesses, and Step S106 is reached. At Step S106, a conductivity test and an appearance inspection are carried out for the wiring harness. At Step S107, the wiring harness is shipped to a motor vehicle manufacturer or the like.
On the other hand, various demands arise from users for the motor vehicle. That is, the motor vehicle is expected to have various kinds of electronic equipment. Consequently, the wiring harness sometimes consists of not less than 100 kinds of the electric wires and various kinds of parts such as the connector housing and the grommet. A motor vehicle is required to be of low cost and to be assembled in a shortest period of time.
Therefore, a factory to manufacture or assemble the wiring harness has to stock not less than 100 kinds of electric wires and various kinds of parts before receiving the order for the wiring harness from a motor vehicle manufacturer. Therefore, the factory of the wiring harness has to keep a very large space for the electric wires and the parts.
In the wiring harness production method of FIG. 16, a step of once stocking the electric wires is required between Step S101 and Step S102 and between Step S102 and Step S103. The electric wire and the parts are also once stocked between Step S103 and Step S104. Further, the sub-harness is once stocked between Step S104 and Step S105. As described, in the prior art production method, the number of the electric wires and the parts to be stocked once is very large. Since there are many kinds of the electric wires and the parts, the number of the electric wires and the parts to be stocked once further increases.
Therefore, in the prior art wiring harness production method of FIG. 16, the space to once stock the electric wires and the parts are required in a factory of the wiring harness. Therefore, the production efficiency of the wiring harness is not good.
In view of the foregoing, an object of the present invention is to provide a wiring harness job-order production method and a wiring harness job-order production system, wherein a space for producing a wiring harness is reduced and the production efficiency of the wiring harness is improved.